Bullet



3,345,949 BULLET John A. Nosler, Bend, Greg., assignor to Nosler Partition Bullet Company, Bend, Oreg. Filed Sept. 27, 1965, Ser. No. 490,331 Claims. (Cl. M12-92.2)

ABSTRACT 0F THE DISCLGSURE A bullet having a jacket of ductile material formed with a tapered nose, a mid sectional area of groove diameter and a rear shank of bore diameter relating to the groove and bore diameters of the rifle in which it is to be used. Spaced along the shank are rolled annular grooves and ridges having a maximum diameter equal to the rifie groove diameter and a minimum diameter less than the rifle bore diameter. The grooves and ridges are spaced from the mid sectional area of the jacket and preferably are formed in two longitudinally spaced groups along the length of the shank.

This invention relates to a novel bullet.

The bullet described herein is provided with a new eX- terior configuration which has for its principal object an increase in accuracy and velocity. The bullet is adaptable to modern high-speed rifles, particularly magnum and super-speed 22 caliber rifies. Late improvements in 22 caliber rifles and cartridges have made this weapon suitable for hunting purposes, =but conventional jaeketed bullets lack the feature of controlled expansion and do not take full advantage of the velocity potential since they do not adapt to barrel configuration or the increased bullet distortion that occurs in the magnum riiie barrel.

It is a first object of this invention to provide a bullet having an exterior configuration that does adapt to barrel configuration and that utilizes the distortion of the bullet to increase the speed thereof rather than to limit it.

Another object of this invention is to provide a bullet with a minimum longitudinal contact area with the rifie barrel, the contact being spread longitudinally along the length of the bullet for greater accuracy.

Another object of this invention is to provide a bullet wherein the contact with the riding inside the riiie barrel is created by relatively thin surface areas capa-ble of deforming under the pressure of the impelling gases so as to seal the bullet as it expands and travels along the length of the rifle barrel.

These and further objects will be evident from a study of the enclosed drawings and from the following description. However, it is to be understood that this description is not intended to limit the scope of my invention, which is defined in the claims that follow.

In the drawings:

FIGURE 1 is a side elevation view of a bullet;

FIGURE 2 is a sectional view cut through the center of the bullet shown in FIGURE 1 along line 2 2; and

FIGURE 3 is an enlarged sectional view of a single band of grooves and ridges along the bullet shank.

The bullet used for illustration in this description is termed a 22 caliber bullet, having a nominal diameter of .224 inch. It includes a jacket that is manufactured by impact extrusion from a ductile copper-zinc alloy. The shank or rear portion 11 of the jacket 10, which is solid, is manufactured to bore diameter for the rifie barrel. The forward cavity in the jacket 10 is filled with a body of lead 12. The mid-sectional area that joins the nose of the bullet to shank 11 is designated by the numeral 13 and has an outside diameter equal to the groove diameter of the rifle barrel.

nited States Patent Formed along the shank 11 in two spaced groups longitudinally displaced from both the rear end 14 of the bullet and the mid-sectional area 13, are two bands of raised grooves and ridges designated as 15 and 16 and shown in enlarged detail in FIGURE 3. The grooves and ridges 15, 16 are preferably rolled into the shank 11 after forming of the jacket 10.

The bullet structure illustrated is manufactured by impact extrusion. The soft interior body of lead 12 permits the forward section of jacket 1d to expand at its target, pulling it back to the solid base provided by shank 11. The forward wall of jacket 10 is of tapered thickness, providing the desired control of expansion, which, together with the solid deep base of shank 11, permits retention of enough weight to give exceptionally deep penetration in game animals.

It is important to note that the shank 11, being solid metal, is formed at bore diameter and is not forced into the grooves of the barrel riiiing. It rides on top of the grooves and is perfectly piloted on the rified lands, which are the more accurately defined elements of the inner barrel surfacing. The solid shank 11 is rolled between rollers that indent to a specific depth and force the displaced material into the roller grooves to provide a series of angular V-shaped rings and grooves around the bullet periphery. The diameter at the ridges or tops of the V- shaped rings is preferably groove diameter and the valleys are preferably less than bore diameter.

Taking a 22 caliber bullet as an example, the bullet has a groove diameter of .224 inch and a bore diameter of .219 inch. There is therefore .0025 inch difference in these diameters at each side of the bullet. To form degree grooves and ridges, the rollers have a surface configuration cut .005 inch deep and .013 inch apart, i.e. from ridge to ridge or valley to valley. This produces a V-shaped configuration on the shank 11 that is .0025 inch deep relative to the illustrated bore diameter and .0025 inch above this same diameter for a total of .005 inch from bottom of valley to top of ridge. For other caliber bullets, the bore and groove relationship differs, but the bullet and for-ming roller grooves would be cut correspondingly wider and deeper to maintain the 90 degree angle centered about a radial plane through the bullet longitudinal axis. A 90 degree ridge and groove configuration has been found best suited to provide the strength to rotate the bullet without stripping the ridge even when used on a bore sized bullet. The 90 degree relationship is achieved by forming the groove and ridge surfaces at 45 degree angles relative to radial planes cut through the bullet.

The 90 degree relationship in the groove and ridge areas 15, 16, shown in FIGURE 3, has been found to provide sufiicient contact with the groove diameter of the riiied -bore and also to conform to the rifling readily so as to properly rotate the bullet. Other angles often create unnecessary pressure or are insufiiciently strong. The described angular relationship, depth of the valleys and proportion of the ridges relative to the valley provide stability in the bullet for flight and therefore improve the accuracy of the bullet over conventional type bands used on previous bullets.

The thin outer edges of the ridges are bent slightly backwards by the forward motion of the bullet during passage through the riiie barrel. At the same time the forward pressure of the gases behind the bullet wed ge these trailing edges against the wall of the barrel. This creates a gas check and promotes increased velocity. In this manner, the grooves and ridges improve the gas check without undue friction, resulting in improved velocity.

A solid base bullet as illustrated, if not reduced in diameter, would create excessive pressures. If the solid based bullet was merely reduced to bore diameter at the solid base, the bearing surface in front of the solid base might not be sufliciently long to insure gas sealage, proper stabilization and accuracy. The two sets of valleys and ridges 15, 16 together with the mid-sectional area 13 provide three areas of contact with the riing of a barrel, each area being longitudinally spaced from the other. They cooperate to stabilize motion of the bullet as it passes through the rie barrel.

The use of the circular ridges as illustrated provides a minimum amount of frictional resistance to motion of the bullet, while actually improving the sealing qualities of the bullet as it travels along the length of a rie barrel. The distortion of the bullet occurs entirely along the valleys and ridges and the body of the bullet itself does not lengthen or distort. The bulk of the bullet shank is guided by contact with the lands on the riing. Since these lands are generally the most accurate part of the rifle barrel, being finished by honing, the maximum accuracy in control of direction of the bullet is thereby achieved.

Various modifications could be made in the specic coniiguration of the bullet without deviating from my basic invention, which is dened in the following claims. Therefore, such obvious improvements are intended to be included within the scope of this disclosure.

Having thus described my invention, I claim:

l. An improvement in a bullet for ring in a rifled barrel having an inside groove diameter and reduced bore diameter, wherein the bullet is formed with an exterior jacket of ductile metal alloy, said jacket comprising:

a nose section of forwardly tapered outside diameter;

a mid-sectional area joining said nose section having an outside diameter equal to the groove diameter;

and a shank joining said mid-sectional area and extending to the rear end of the bullet, said shank having an outside diameter equal to the bore diameter and having formed thereon a series of raised annular grooves and ridges having a maximum diameter equal to the groove diameter and a minimum diameter less than the bore diameter, said grooves and ridges being longitudinally spaced from said midsectional area and being each oriented perpendicular to the bullet axis.

2. A bullet as dened in claim 1 wherein said grooves and ridges on said shank are formed by intersecting rolled surfaces.

3. A bullet as dened in claim 1 wherein said grooves and ridges on said shank are formed by surfaces which intersect one another at 45 degree angles relative to radial planes cut through the bullet.

4. A bullet as defined in claim 1 wherein said grooves and ridges on said shank are formed in two sets longitudinally spaced from one another and respectively spaced longitudinally from the rear end of the bullet and said mid-sectional area.

5. A bullet as defined in claim 1 wherein said grooves and ridges on said shank are formed in two sets longitudinally spaced from one another and respectively spaced longitudinally from the rear end of the bullet and said mid-sectional area;

said grooves and ridges on said shank being formed by surfaces Which intersect one another at right angles and which individually form 45 degree angles relative to the radial planes cut through the bullet.

References Cited FOREIGN PATENTS 9/ 1920 France. 10/1934 France.

1/ 1943 Germany. 

1. AN IMPROVEMENT IN A BULLET FOR FIRING IN A RIFLED BARREL HAVING AN INSIDE GROOVE DIAMETER AND REDUCED BORE DIAMETER, WHEREIN THE BULLET IS FORMED WITH AN EXTERIOR JACKET OF DUCTILE METAL ALLOY, SAID JACKET COMPRISING: A NOSE SECTION OF FORWARDLY TAPERED OUTSIDE DIAMETER; A MID-SECTIONAL AREA JOINING SAID NOSE SECTION HAVING AN OUTSIDE DIMETER EQUAL TO THE GROOVE DIAMETER; AND A SHANK JOINING SAID MID-SECTIONAL AREA AND EXTENDING TO THE REAR END OF THE BULLET, SAID SHANK HAVING AN OUTSIDE DIAMETER EQUAL TO THE BORE DIAMETER AND HAVING FORMED THEREON A SERIES OF RAISED ANNULAR GROOVES AND RIDGES HAVING A MAXIMUM DIAMETER EQUAL TO THE GROOVE DIAMETER AND A MINIMUM DIAMETER LESS THAN THE BORE DIAMETER, SAID GROOVES AND RIDGES BEING LONGITUDINALL SPACED FROM SAID MIDSECTIONAL AREA AND BEING EACH ORIENTED PERPENDICULAR TO THE BULLET AXIS. 